.pyc files are always removed from the bundle, .py files are removed
if a .pyo file exists. This reduces the size of the zipped bundle to
40MB (including compounds.chemlib, excluding the examples).

git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/trunk@2464 5a81b35b-ba03-0410-adc8-b2c5c5119f08